512 CENTETES AND ITS ALLIES CHAP. annoyed. The Tanrec feeds mainly upon earthworms. It is " probably the most prolific of all animals," since as many as twenty-one young are said to have been brought forth at a birth. Some Opossums, however, have twenty-five teats. Uemicentetes1 is a genus with two species. These have spines mixed with the fur of the back. There is no caecum in this or FIG. 248.—Skull of Tenrec. Centetes ecaudatus. fr, Frontal ; max, maxilla ; pat parietal; p.tnax, premaxilla ; sgr, squamosal. (After Dobsoii.) in other Gentetidae. The teeth are forty in number, there being only three molars. Ericulus setosus is a small Insectivore, resembling externally a small Hedgehog. It is covered with close-set spines which, unlike what is found in Jflrinaceus, extend over the short tail. The total number of teeth is thirty-six, the formula being If Ci Pmf Mf. JSchinogs2 is another spiny genus which is a stage in advance of Ericulus, for still another molar has been lost, reducing the total number of teeth to thirty-two. The dental formula is thus I •§• C -J- 3?m ^ M -J-. The zygomata are reduced to mere threads. M/iGrogale, a genus recently instituted by Mr. Thomas, is a small furry Insectivore with a long tail, which is more than double the length of the head and body. There are no less than forty-seven vertebrae in the tail, which is relatively longer than that of any other mammal. Inmnogcde, discovered by Forsyth Major, is an aquatic genus, also furry and not spiny, which has departed from the Cente- tid tvpe and taken to an aq[uatic life. The single species, 1 Mivart in JProc. Zool. Soc. 1871, p. 58. 2 Thomas,, Proc, Zool. Soc. 1892, p. 500.